Bromocriptine ((5′α)-2-bromo-12′-hydroxy-2′-(1-methylethyl)-5′-(2-methylpropyl)-ergotaman-3′,6′,18-trione, CAS Registry No. 25614-03-3) is an ergot alkaloid which is a potent dopamine D2 receptor agonist. The compound has the following formula:

Solid oral dosage forms of bromocriptine are available as bromocriptine mesylate (5′α)-2-bromo-12′-hydroxy-2′-(1-methylethyl)-5′-(2-methylpropyl)-ergotaman-3′,6′,18-trione monomethanesulfonate salt, CAS Registry No. 22260-51-1) in a tablet containing up to 2.5 mg bromocriptine or in capsule form containing 5 mg bromocriptine. Bromocriptine is useful in the treatment of certain hyperprolactinemia-associated dysfunctions and acromegaly, in the prevention of physiological lactation, and in the treatment of Parkinson's disease and prevention of tolerance to Levodopa therapy for Parkinson's disease. In clinical trials, adverse effects included nausea, headache, dizziness, fatigue, lightheadedness, vomiting, abdominal cramps, nasal congestion, constipation, diarrhea and drowsiness. When bromocriptine is used as described above, prolactin is reduced to low levels throughout a 24 hour period.
U.S. Pat. Nos. 5,344,832, 5,554,623 and 5,716,957 discuss a method for modifying and regulating lipid and glucose metabolism by administering a dopamine agonist, e.g., bromocriptine, and/or a prolactin stimulator to reset hormonal timing in the neural centers of the brain to control insulin resistance, hyperinsulinemia and hyperglycemia.
U.S. Pat. Nos. 5,468,755, 5,756,513 and 5,866,584 discuss a method to modify and regulate lipid and carbohydrate metabolism-generally to reduce obesity, insulin resistance, hyperinsulinemia and hyperglycemia, by administration of a dopamine agonist such as bromocriptine to inhibit prolactin over a limited period at a time of day to reset normal hormonal timing and control insulin resistance, hyperinsulinemia and hyperglycemia.
U.S. Pat. No. 5,679,685 discusses accelerated release bromocriptine mesylate formulations for regulating prolactin levels that are abnormal during particular times during the day.
WO/2009/091576 discusses compositions for parenteral administration using dopamine agonists such as bromocriptine, that are described as being useful for treating metabolic-related conditions such as type 2 diabetes.
CYCLOSET®, a tablet form of bromocriptine mesylate providing a 0.8 mg dose of bromocriptine, is FDA approved for once-daily administration to improve glycemic control adults with type 2 diabetes mellitus, at a dose of 2-6 tablets (1.6 to 4.8 mg total dose).